1. Field of the Invention
The present invention relates to an optical connector including a coil spring that impresses an optical ferrule and a spring pressing portion that receives a reaction force of the coil spring, and more particularly, to the spring pressing portion.
2. Description of Related Art
As an optical connector including a coil spring that impresses an optical ferrule and a spring pressing portion that receives a reaction force of the coil spring, there is an F13-type multi-core optical fiber connector described in JIS C5982, which is a so-called MPO optical connector. FIGS. 10A to 12 show this kind of conventional optical connector (MPO optical connector) 51.
The optical connector 51 has the following basic structure (see Japanese Patent Application, Publication No. 2002-148485). In a connector housing 52, an optical ferrule 53 obtained by inserting and fixing a front end of optical fibers and then performing a terminating work, and a coil spring 54 that impresses the optical ferrule 53 in a forward are housed, and a spring pressing portion 55 is attached to a rear end side of the connector housing 52. The spring pressing portion 55 receives a reaction force of the coil spring 54. A coupling 56 for attachment to and detachment from an adaptor 50 that is a connector coupling portion is mounted on an outer periphery of the connector housing 52 together with a coupling spring 57, and a rubber boot 59 for protecting a periphery of a connector opening portion of an optical fiber cord (optical fiber tape in the shown example) 58 is attached to a rear portion of the spring pressing portion 55. Reference numeral 58a denotes an optical fiber portion (a part of forming a tape shape in which plural lines of optical fibers come into close contact with each other) from which a coating of the optical fiber cord 58 is removed, and reference numeral 58b is a coating portion (cord portion) of the optical fiber cord 58. Each of the optical fibers is obtained by performing a first coating on a bare fiber, for example, an outer diameter thereof is 0.25 mm.
When the optical connector 51 is connected to the adaptor 50 shown in FIG. 12, an opposite optical connector (not shown) connected to the adaptor 50 from the opposite side thereof and the optical ferrule 53 face each other, thereby optically connecting the optical fibers to each other.
As shown in a perspective view of FIG. 11, the spring pressing portion 55 is a resin molding article having an optical fiber inserting through-hole 55a for passing the optical fibers therethrough, a spring reception portion 55b that receives a reaction force of the coil spring 54, and an engagement claw 55c that engages with an engagement hole 52a of the connector housing 52. As shown in the same figure, the conventional spring pressing portion 55 is an integrally molded article.
In assembly of the optical connector 51, the optical ferrule 53 is attached to the front end of the optical fibers to grind the end face thereof. At that time, it is necessary to pass the optical fibers into a plurality of components. That is, it is necessary to pass the optical fibers into the rubber boot 59, the spring pressing portion 55, and the coil spring 54.
Among these components, particularly, the optical fiber inserting through-hole 55a of the spring pressing portion 55 has an inner diameter capable of passing the optical fiber portion 58a of the optical fiber cord 58, and has no room for passing the coating portion (cord portion) 58b. In addition, there is room in the sectional view of FIG. 10A shown by the section of the cord along the widthwise direction, but there is no room in the thickness direction (thickness direction of the optical fiber tape, vertical direction in FIG. 10B) of the cord.
Meanwhile, since a length of the optical fiber portion 58a of the cord is regulated to a predetermined length or less, it is difficult to secure sufficient room length of the optical fiber portion 58a in the optical connector 51. Accordingly, the spring 54 and the spring pressing portion 55 covering the optical fiber portion 58a are disposed close to each other because it is difficult to sufficiently detach them from the rear end face of the optical ferrule 53.
As a result, at the time of the terminating an operation of the optical ferrule 53, there is a problem that the spring pressing portion 55 covering the optical fiber portion 58a causes interference in the operation. In addition, although the spring 54 similarly causes interference in the operation, there is no interference such as the case of the spring pressing portion 55 because the spring 54 is made of expandable, contractible, and flexible materials. Herein, the terminating the operation of the optical ferrule indicates an operation of attaching the optical ferrule to the front end of the optical fibers and grinding the section thereof.